The present invention relates to wireless security systems and in particular to wireless security systems having remote indication devices that provide feedback to a user.
A recent innovation in security system applications is the use of wireless bi-directional consoles or display units, which are portable wireless devices that control and interrogate the security system for status. For example, two such wireless bi-directional consoles (5827BD and 5804BD) are manufactured by Alarm Device Manufacturing Company (Ademco) 165 Eileen Way, Syosset, N.Y. 11791. Wireless bi-directional consoles have the advantage of portability if required, or may be permanently mounted, thereby reducing the additional cost of wiring a conventional wired console. Prior art devices of this type include a wireless transmitter and a wireless receiver. The wireless transmitter transmits control commands and status requests to a central receiver in communication with a central control system. The wireless receiver receives confirmation of the control command and status information which is transmitted from a central transmitter also in communication with the central control unit. The confirmation or status is then displayed to the user on the wireless bi-directional console.
A disadvantage of this approach is that the wireless bi-directional console, due to the inclusion of a receiver, is physically larger and significantly more expensive than a unidirectional ("transmit only") device. The additional size and cost of such units becomes particularly prohibitive in commercial installations where a large number of wireless bi-directional consoles may be in use at any given time. In such a multi-user environment, the additional cost of portable transceivers generally forces the user to install unidirectional devices rather than their bi-directional counterparts.
Therefore, it would be advantageous if the size and cost of wireless bi-directional consoles in multi-user environments could be reduced while providing a practical means for transmitting control commands and status requests to and obtaining confirmation and status from the central control unit.
One solution has been to provide a wired remote indication device that operates from AC power. The wired remote indication device displays status and confirmation of commands to the user within a relatively short range from the central control unit. However, strategic positioning of such a wired remote indication device to provide optimal site coverage, wireless propagation characteristics, and visibility to the user may not be near enough to an AC power source. The installer of such a security system must either compromise the optimal location of the device or install a potentially expensive power line to the device, thereby negating the advantages of an otherwise wireless installation.
Therefore, it would be advantageous if a remote indication device could be entirely wireless, thus enabling its installation to be optimized with respect to wireless signal propagation and visibility of the display to the user without regard to the location of AC power sources.